Cardiomyopathy is a disease that weakens and enlarges heart muscle, and can lead to heart failure. Heart failure is the most common hospital discharge diagnosis and accounts in the United States. Dilated cardiomyopathy (DCM) is a relatively common condition (estimated prevalence 1:2500) 36.5 per 100,000 in Olmsted County, Minn. (Cetta and Michels, Ann. Med. 27, 169-173 1995) and is the third leading cause of heart failure. The clinical course of DCM is usually one of inexorable decline punctuated by acute decompensation. As a result, DCM remains the most frequent indication for cardiac transplantation. Despite the high mortality, morbidity and costs associated with DCM, the pathophysiology of this condition is largely unknown, and almost half do not have an identifiable etiology and are labeled as having idiopathic DCM (Felker, G M et al, Medicine 78(4): 270-283, 1999). Current management of DCM provides only supportive therapy rather than treating an underlying cause. As a result, once heart failure is established in a patient with DCM, the expected outcome is poor, with a 5 year mortality of about 46% (Felker et al., The New England journal of medicine. 2000; 342:1077-1084).